Abstract: The present disclosure relates to assemblies for engines such as pre-combustion chamber assemblies for spark ignition engines. In one example, a pre-combustion chamber assembly includes an ignition chamber adapted to contain at least one electrode of a spark generator. The ignition chamber being adapted to communicate with a main engine combustion chamber via a plurality of pre-chamber ports. The ignition chamber communicates for removal therefrom of exhaust gas residuals to a distinct storage chamber via at least one transfer port. The ignition chamber includes a single substantially cylindrical entrance channel leading from said pre-chamber ports in a direction towards an ignition region of the ignition chamber. The ignition region having a larger cross-section than the entrance channel.

Abstract: The present disclosure relates to assemblies for engines such as pre-combustion chamber assemblies for spark ignition engines. It is known to provide a spark ignition engine with a pre-combustion chamber but it can be difficult to provide a system with good knock performance at high speed with high loads while still having reliable ignition at low speed with low load. In particular, at low speed with low load, there may be a relatively high percentage of exhaust gas residuals (EGR) in a pre-combustion chamber which can prevent ignition especially when the ignition timing is retarded during catalyst heating. Aspects of the disclosure aim to alleviate at least to a certain extent the problems of the prior art.

Abstract: The present disclosure relates to assemblies for engines such as pre-combustion chamber assemblies for spark ignition engines. It is known to provide a spark ignition engine with a pre-combustion chamber but it can be difficult to provide a system with good knock performance at high speed with high loads while still having reliable ignition at low speed with low load. In particular, at low speed with low load, there may be a relatively high percentage of exhaust gas residuals (EGR) in a pre-combustion chamber which can prevent ignition especially when the ignition timing is retarded during catalyst heating. Aspects of the disclosure aim to alleviate at least to a certain extent the problems of the prior art.